Police watchdog bosses were today branded as 'shameless' as they failed to publish the findings of their four-year inquiry into the botched Kevin Nunes gangland murder investigation – two years after it was completed.

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The country lane where the body of Kevin Nunes, inset, was found

Staffordshire Police and the Independent Police Complaints Commission also face accusations of 'colluding to hide' what happened as it was admitted discussions were taking place over what information will be made public.

The IPCC's Operation Kalmia report – believed to have cost taxpayers in the region of £7 million – outlines serious failings by detectives that led to the murder convictions of five men jailed for the 2002 firing squad-style killing being overturned in 2012.

Fourteen police officers – including the current Staffordshire chief constable and a West Midlands assistant chief constable – were investigated. Apart from one officer receiving 'management advice' not a single other officer has faced disciplinary action despite recommendations to the contrary. The Crown Prosecution Service also decided against bringing criminal charges.

The Shropshire Star later this week intends to publish previously unknown details from the calamitous murder probe garnered over our own investigations spanning nearly three years. Today the two-year delay to publish the report was criticised by Inspector-turned-whistleblower Joe Anderson who first exposed wrongdoing and failings within Staffordshire Police's Sensitive Policing Unit in 2006 – a year before the Nunes case went to court.

He said: "Staffordshire Police and the IPCC have in my opinion colluded together to hide the contents of reports which reveal what went on. The family of Mr Nunes and the general public have a right to know what went on."

South Staffordshire MP Gavin Williamson said: "I think it is a disgrace and shameless that it has taken so long to deal with."

Mr Nunes, aged 20, from Whitmore Reans, Wolverhampton was shot in the South Staffordshire countryside 14 years ago by rival drug dealers from notorious West Midlands gangs. His bullet-ridden body was found in Clive Road, Pattingham, near the Shropshire border, in 2002.

An IPCC spokesman said: "Due to the complexity and length of the report and supporting evidence, the legally-required consultation with interested parties and reviewing any necessary redactions, this process is currently ongoing. We will look to publish a report in due course."

Staffordshire's Deputy Chief Constable Nick Baker said: "The contents of this report and its publication are solely the responsibility of the Independent Police Complaints Commission, and as such we are unable to add any further comment."